JP2008232077A - Steam ejector, decompression system constructed by use of steam ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam ejector capable of increasing operation effect and reducing running cost by operating with optimal drive steam pressure through a year irrespective of outside temperature or the like. <P>SOLUTION: The steam ejector 6 having ejection parts 61, 62 ejecting steam is provided with an ejection part group comprising a plurality of the ejection parts 61, 62. A plurality of ejection parts 61, 62 of the ejection part group are selectively used based on at least one condition of an upstream side condition and a downstream side condition of the ejection part group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steam ejector and a decompression system configured using the steam ejector.

  Conventionally, various systems have been proposed for a system that effectively uses energy. For example, a system that recovers retained heat of exhaust gas discharged from an engine by an exhaust gas boiler is known. . In this system, effective use of energy is achieved by using steam generated by an exhaust gas boiler for cooling and heating.

  In the above system, the overall system configuration such as the type and quantity of equipment that uses steam is designed based on the amount and temperature of exhaust gas emitted from the engine. Extra steam may be generated depending on the load status of the equipment using the steam generated in the exhaust gas boiler. That is, there may be a surplus of steam generated in the exhaust gas boiler depending on the status of each device constituting the system. In such a case, a bypass path is provided in the system so that the exhaust gas from the engine is not input to the exhaust gas boiler to interrupt the generation of steam, or the excess steam generated by the exhaust gas boiler is released to the atmosphere. I was doing. That is, in such a conventional system, the effective use of energy has not been sufficiently achieved.

  As a system using steam generated in an exhaust gas boiler, for example, there is a system described in Patent Document 1 (hereinafter, referred to as “system according to prior art”). In the system according to this prior art, electric power is obtained by operating a generator by an engine, and exhaust gas discharged from the engine is sent to an exhaust gas boiler. Then, the steam generated in the exhaust gas boiler is passed through the steam ejector to obtain steam from the vacuum evaporator, and the steam is sent to the steam utilization equipment, and the condensed water obtained there passes through the drain tank and water softener. It is made to circulate to an exhaust gas boiler.

  That is, in the system according to the prior art, effective use of energy is achieved by using a steam ejector.

JP 20024943 A

  However, the system using the steam ejector including the system according to the related art described above has the following problems.

  The operating range of the steam ejector is normally set so that the maximum radiant pressure (Pmax) of the steam ejector is set on the basis of the summer when the discharge side pressure (condenser side pressure) (Pout) of the steam ejector is the highest (“Pmax> Therefore, there is a problem that energy cannot be used efficiently throughout the year.

  More specifically, during operation in winter, the condenser cooling water temperature is low, and the discharge side pressure (condenser side pressure) of the steam ejector is low. However, since the steam ejector performs pressure boosting work similar to that in summer, the steam ejector in winter (that is, when the temperature is low) performs pressure boosting work more than necessary. That is, in the steam ejector according to the prior art, even when the temperature is low, the same driving steam as when the temperature is high is consumed, and the effective use of energy cannot be achieved.

  In addition, for example, when a cold water production system (an example of a decompression system) is configured using a steam ejector having one nozzle part (spout part), the suction side pressure increases and the pressure increase pressure decreases as the cold water production temperature increases. However, there was a problem that if the same amount of driving steam was used, pressure boosting work would be performed more than necessary.

  Furthermore, when the nozzle part (spouting part) is designed with the optimum nozzle expansion ratio and the optimum driving steam amount in one season (for example, summer), to reduce the driving steam amount in the other season (for example, winter). When the driving steam pressure is lowered, there is a problem that the driving steam is excessively expanded and the performance is lowered.

  Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and it is possible to operate in an optimum state throughout the year regardless of the outside air temperature, etc., to increase the operation efficiency and reduce the running cost. An object is to provide a steam ejector that can be used.

  Moreover, this invention makes it a subject to provide the pressure reduction system (for example, cold water manufacturing system) comprised using the steam ejector mentioned above. For example, a cold water production system (decompression system) using such a steam ejector can produce cold water using surplus steam, so that the running cost of the entire system can be kept low. Further, since cold water can be produced without using any refrigerant, an environment-friendly cold water production system (decompression system) can be configured. Furthermore, as a whole chilled water production system (decompression system), it is possible to improve the operation rate of a boiler (for example, an exhaust gas boiler) and reduce the amount of contract power.

  The present invention has been made in order to solve the above-described problems, and is a steam ejector having a jetting part for jetting steam, wherein a jetting part group including a plurality of the jetting parts is provided, and the jetting part is provided. One or two or more ejection parts in the ejection part group are selectively used based on at least one of the upstream condition and the downstream condition of the group. Here, examples of the upstream condition include a cold water production temperature of a cold water production system configured using a steam ejector. Moreover, as downstream conditions, a condenser cooling water temperature etc. are mention | raise | lifted, for example.

  According to such a configuration, the steam ejector includes the ejection part group including a plurality of ejection parts, and the ejection part is based on at least one of an upstream condition and a downstream condition of the ejection part group. Since one or two or more jets in the group are selectively used, it is possible to operate in an optimal state throughout the year regardless of various conditions such as outside air temperature, to increase operating efficiency and reduce running costs. A steam ejector can be obtained.

  Moreover, in the steam ejector concerning this invention, it is preferable that the said ejection part group is comprised using a different kind of ejection part. The present invention includes not only the case where the ejection part group is composed of only different types of ejection parts, but also the case where the same kind of ejection part is used in combination with different types of ejection parts. It is.

  Moreover, in the steam ejector concerning this invention, it is preferable that the said ejection part group is comprised using the ejection part which has a different nozzle throat diameter.

  According to this preferred configuration, since a plurality of jetting portions having different nozzle throat diameters are provided, by selectively using one or two or more of these jetting portions as required, the outside air temperature or the like Regardless of the operation, it is possible to drive in the optimum state, increase the driving efficiency and reduce the running cost. More specifically, for example, even when the condenser cooling water temperature fluctuates depending on the season, it is possible to operate with an effective driving steam amount by selectively using the ejection portion having a different nozzle throat diameter. Therefore, there is no excessive expansion or insufficient expansion, and the operation efficiency can be improved.

  Moreover, in the steam ejector concerning this invention, it is preferable that the said ejection part group is comprised using the ejection part which has a different nozzle expansion ratio.

  According to this preferable configuration, since a plurality of ejection portions having different nozzle expansion ratios are provided, it is optimal throughout the year by selectively using one or more of these ejection portions as necessary. Driving in a safe state, driving efficiency can be increased and running cost can be reduced. More specifically, for example, when a chilled water production system is configured using this steam ejector, even if the chilled water production temperature fluctuates, it is effective by selectively using an ejection portion having a different nozzle expansion ratio. Since the operation with the driving steam amount becomes possible (for example, the usage amount of the driving steam can be reduced), the operation efficiency can be improved.

  The present invention has been made in order to solve the above-described problem, and is a steam ejector having an ejection part for ejecting steam, wherein a plurality of unit steam ejectors having one or more ejection parts are provided, One or more of the unit steam ejectors are selectively used based on at least one of an upstream condition and a downstream condition of the unit steam ejector. That is, in the present invention, a steam ejector is configured using a plurality of unit steam ejectors, and the unit steam ejector is switched based on at least one of the upstream condition and the downstream condition of the unit steam ejector. Configured for use. Further, a plurality of ejection portions may be provided in the unit steam ejector, and the ejection portions may be selectively switched in the unit steam ejector as necessary.

  According to such a configuration, one or more of the unit steam ejectors are selectively used based on at least one of the upstream condition and the downstream condition of the unit steam ejector. Regardless of various conditions, it is possible to obtain a steam ejector that can be operated in an optimal state throughout the year and that can increase the operating efficiency and reduce the running cost.

  Furthermore, the present invention has been made to solve the above problems, and is a decompression system configured using a steam ejector, wherein the steam ejector is a steam ejector according to any one of the above-described configurations. It is characterized by.

  According to such a configuration, by configuring the decompression system using the above-described steam ejector, it is possible to obtain a decompression system that is driven efficiently regardless of the outside air temperature or the like. For example, when configuring a cold water production system (an example of a decompression system), it is possible to produce cold water using surplus steam, so that the running cost of the entire system can be kept low. Further, since cold water can be produced without using any refrigerant, an environment-friendly cold water production system can be configured. Furthermore, as a whole cold water production system, it is possible to improve the operating rate of a boiler (for example, an exhaust gas boiler) and reduce the amount of contract power. Of course, the above-described steam ejector itself can be operated with high efficiency, and as a result, the efficiency of the cold water production system can be improved.

  According to the present invention, it is possible to obtain a steam ejector that can be operated in an optimum state throughout the year regardless of the outside air temperature and the like, and that can improve the operation efficiency and reduce the running cost. Further, according to the present invention, it is possible to obtain a decompression system capable of realizing various effects such as reduction in running cost as a whole system.

  Hereinafter, embodiments of the present invention will be described.

  The steam ejector according to the first aspect of the present embodiment is a steam ejector having a jetting part for jetting steam, and is provided with a jetting part group composed of a plurality of the jetting parts, upstream of the jetting part group Based on at least one of the condition and the downstream condition, one or two or more ejection parts in the ejection part group are configured to be selectively used.

  Moreover, the steam ejector concerning the 2nd aspect of this embodiment is the structure of a 1st aspect, The said ejection part group is comprised using a different kind of ejection part.

  Moreover, the steam ejector concerning the 3rd aspect of this embodiment is comprised in the structure of the 1st aspect or the 2nd aspect using the ejection part in which the said ejection part group has a different nozzle throat diameter.

  Moreover, the steam ejector concerning the 4th aspect of this embodiment is comprised in the structure in any one of a 1st aspect to a 3rd aspect using the ejection part in which the said ejection part group has a different nozzle expansion ratio. .

  Further, the steam ejector according to the fifth aspect of the present embodiment is a steam ejector having an ejection part for ejecting steam, and a plurality of unit steam ejectors having one or more ejection parts are provided, and the unit steam One or more unit steam ejectors are configured to be selectively used based on at least one of the upstream condition and the downstream condition of the ejector.

  Furthermore, the decompression system (for example, cold water production system) according to the sixth aspect of the present embodiment is a decompression system configured using a steam ejector, and the steam ejector is any one of the first to fifth aspects. These steam ejectors are used.

  Next, a cold water production system according to an embodiment of the present invention (corresponding to the “decompression system” of the present invention) will be described with reference to the drawings.

  In the following embodiments, as described later, a “cold water production system (cold water production apparatus)” is shown as a system (decompression system) configured using a steam ejector, but the present invention is limited to this configuration. Not. That is, the decompression system configured using the steam ejector (steam ejector capable of effectively using energy) according to the present invention is not limited to the cold water production system, for example, a vacuum thawing system (vacuum thawing machine), Any vacuum system that uses a steam ejector to depressurize the part to be decompressed (for example, a vacuum cooling tower) such as a vacuum cooling system (vacuum cooler), a steam cooling system (steam cooler), etc. Such a system may be used, and any decompression system belongs to the technical scope of the present invention.

  Moreover, the cold water manufacturing system shown in the Example mentioned later shows an example of the system which uses the steam ejector concerning this invention and can use energy effectively, Comprising: The example using the energy produced | generated by (energy source) is shown. More specifically, an example of a system in which exhaust gas from the engine is recovered by an exhaust gas boiler to generate steam and the exhaust gas and steam can be effectively used is shown. However, as a matter of course, the present invention is not limited to this configuration, and even a system configured to effectively use energy generated by another energy source using the steam ejector according to the present invention. It belongs to the technical scope of the present invention.

<First Example>
FIG. 1 is a schematic view of a cold water production system (corresponding to the “decompression system” of the present invention) configured using the steam ejector according to the first embodiment of the present invention. As described above, the cold water production system shown in FIG. 1 shows an example of a system that can effectively use the energy constituted by using the steam ejector according to the present invention.

  As shown in FIG. 1, the cold water production system (effective energy use system) according to the present embodiment is an exhaust gas boiler as a specific example of an engine 1 and a steam generation unit that generates steam using the exhaust gas of the engine 1. 2, a main steam supply line 3 for supplying steam from the exhaust gas boiler 2 to a steam use location (not shown), a first sub-steam supply line 4 separate from the main steam supply line 3, and the first sub-steam supply line 4, a second sub-steam supply line 5 branched from the first sub-steam supply line 4, a steam ejector 6 provided on the downstream side of the first sub-steam supply line 4, and a vacuum cooling tower as a specific example of a portion to be decompressed connected to the steam ejector 6 7. Condensate 8a is discharged from the condenser 8 for condensing the steam that has passed through the steam ejector 6, the water-sealed vacuum pump 9 as a specific example of the decompression means for decompressing the inside of the condenser 8, and the condenser 8. It is formed by using the cooling tower 11 or the like for exchanging heat between the discharge pump 10 and the condenser 8, the specific examples of condensation water discharging means.

  For example, the engine 1 is configured to operate a generator (not shown) and to send exhaust gas discharged when the engine 1 is operated to the exhaust gas boiler 2. That is, the engine 1 is connected to the exhaust gas boiler 2 in order to effectively use the exhaust gas generated at that time in addition to exhibiting the main function (here, the function of “activating the generator”). Yes.

  The exhaust gas boiler 2 corresponds to a steam generation unit, and generates steam using the exhaust gas from the engine 1. The exhaust gas boiler 2 according to the present embodiment is connected to a main steam supply line 3 that supplies the generated steam to a place where the steam is used, and a first auxiliary steam supply line 4 that supplies surplus steam to the steam ejector 6. Furthermore, a second sub-steam supply line 5 is provided that branches off from the first sub-steam supply line 4. The first auxiliary steam supply line 4 is provided with a motor valve 16 in order to control the driving steam pressure supplied to the steam ejector 6. The exhaust gas boiler 2 is supplied with, for example, makeup water (condensed water) from a condenser 8 described later, and degassed soft water via a water softener (not shown) or a deaerator (not shown). The combined water is sent as water supply.

  The vacuum cooling tower 7 corresponds to a portion to be decompressed, and is configured to supply treated water to the inside of the main body of the vacuum cooling tower 7 via the treated water supply line 12. And if the treated water supplied in this way is sprinkled from the treated water spray part 7A provided in the upper position of the main body, the treated water is deprived of the latent heat of evaporation and becomes cold water 7a. The cold water 7a thus obtained is sent to a cold water use location (or cold water storage location) using the cold water feed pump 13 and used as appropriate.

  As the condenser 8, for example, a shell and tube heat exchanger is used. In the shell and tube heat exchanger, a plurality of tubes into which steam can be introduced are erected with a predetermined interval, and cooling water supplied from the cooling tower 11 is supplied from the cooling water line 14. When the cooling water comes into contact with the outside of the tube, the steam and the cooling water are configured to indirectly exchange heat. The cooling water is heat-exchanged with the steam, then returned to the cooling tower 11, cooled by the cooling tower 11, and circulated again to the condenser 8 (shell and tube heat exchanger).

  The water-sealed vacuum pump 9 corresponds to a decompression means. By bringing the inside of the condenser 8 into a decompressed state, the steam from the steam ejector 6 is actively introduced into the condenser 8 and is non-condensable. It has the role of discharging air as gas. The water-sealed vacuum pump 9 is connected to a position above the stored water level of the condensed water 8a in the condenser 8 in order to prevent the condensed water 8a from being sucked and discharged. Further, the connection location between the water-sealed vacuum pump 9 and the condenser 8 is provided as far as possible from the connection location between the condenser 8 and the steam ejector 6. This is to make it difficult to discharge the vapor before condensation introduced into the condenser 8. Further, the water-sealed vacuum pump 9 can control the processing capacity of the vacuum pump by adjusting the temperature of the sealed water.

  The discharge pump 10 corresponds to a condensed water discharge means for discharging the condensed water 8 a in the condenser 8. The discharge pump 10 functions to discharge the condensed water 8a in the condenser 8 that has been decompressed by the water ring vacuum pump 9 as necessary. The condensed water 8a discharged from the condenser 8 by the discharge pump 10 is stored in, for example, a predetermined storage tank (not shown) and then supplied to the exhaust gas boiler 2, the cooling tower 11 and the like for circulation. Is done.

  As the cooling tower 11, a generally known open type cooling tower is illustrated. The cooling tower 11 has a main body having an opening in the upper portion and a storage tank in the lower portion, a fan 11A provided in the opening for generating an air flow in the main body, and spraying cooling water in the main body. It is comprised using the spreading | diffusion part 11B etc. The cooling water is sprayed from a spraying portion 11B provided at a lower position of the fan 11A, and the sprayed cooling water is cooled by coming into contact with the airflow generated by the fan 11A. The cooling water is stored in a storage tank at the lower part of the main body, and then returns to the cooling tower 11 again through the condenser 8 via the cooling water line 14. The returned cooling water retains heat by heat exchange in the condenser 8, but this heat is partly evaporated by being dispersed in the cooling tower 11 and released from the opening to the atmosphere. The

  A part of the steam generated by the exhaust gas boiler 2 is introduced into the steam ejector 6 through the first sub-steam supply line 4, and this steam passes through the steam ejector 6 and is then introduced into the condenser 8. As described above, when steam is introduced from the first sub-steam supply line 4 to the steam ejector 6, the steam is ejected from the nozzle portion (corresponding to the “ejection portion” of the present invention) in the steam ejector 6. Thus, the inside of the vacuum cooling tower 7 is depressurized by the steam ejection energy via the steam suction line 15 connected to the steam ejector 6. Further, the vapor in the vacuum cooling tower 7 is sucked and mixed in the vapor ejector 6 by the pressure reducing action caused by the vapor ejection energy in the vapor ejector 6, and these vapors are condensed through the vapor ejector 6. Supplied to the container 8 side. In the condenser 8, air, which is a non-condensable gas, is discharged by the water-sealed vacuum pump 9, so that air does not dissolve in the condensed water 8 a in the condenser 8, and thus the condensed water 8 a is degassed. It becomes what was done. Moreover, the vapor | steam discharge | released to the condenser 8 side from the steam ejector 6 is condensed by performing heat exchange between the cooling water introduce | transduced into the condenser 8 from the cooling tower 11, and the condenser 8 is used as the condensed water 8a. Stored inside. Condensed water 8a obtained in this way is obtained by condensing vapor free from impurities from the exhaust gas boiler 2 and the vacuum cooling tower 7, and does not contain air that is a non-condensable gas. That is, since the condensed water 8a is degassed pure water, it is supplied to the exhaust gas boiler 2 and the cooling tower 11 as make-up water as needed, so that the energy can be effectively used.

  As described above, when the condensed water 8a is used as make-up water in the exhaust gas boiler 2, the condensed water 8a is pure water, so that the drainage amount (blow amount) of the concentrated water can be reduced, and calcium, Since there is no hardness such as magnesium, scale adhesion can be suppressed. Moreover, since it is pure water, there is no sulfate ion and chloride ion, which are corrosive factors such as water pipes constituting the exhaust gas boiler 2, and it is degassed, so that the occurrence of corrosion of the water pipes can be suppressed. it can. Furthermore, since the condensed water 8a is warm water, the energy for preheating water supply can be suppressed.

  Further, when this condensed water 8a is used as makeup water for the cooling tower 11, the condensed water 8a does not contain a hardness component, so that the growth of algae, slime and Legionella can be suppressed. Furthermore, since the condensed water 8a is pure water, the concentration of circulating water can be reduced, and the drainage amount (blow amount) of concentrated water can be reduced. Moreover, since there are no sulfate ions and chloride ions, the occurrence of corrosion can be suppressed.

  In the cold water production system according to the present embodiment configured as described above, the steam ejector 6 is functionally configured in order to use energy more effectively. Hereinafter, the configuration of the steam ejector will be specifically described with reference to the drawings.

  FIG. 2 is a schematic diagram illustrating an example of the steam ejector 6 constituting the cold water production system according to the present embodiment. FIG. 3 shows an enlarged cutaway view of a nozzle portion (corresponding to the “spout portion” of the present invention) constituting the steam ejector 6 in FIG. Further, FIG. 4 shows a partially enlarged view of FIG. 3 (enlarged view of part IV).

  As shown in FIG. 2, the steam ejector 6 according to the present embodiment is connected to the first auxiliary steam supply line 4 and the steam suction line 15 at the upper position, and to the condenser 8 at the lower position. Yes. According to the present embodiment, as described above, a part of the steam generated by the exhaust gas boiler 2 is introduced into the steam ejector 6 through the first sub-steam supply line 4, and the steam is sucked by this steam. Through the line 15, the inside of the vacuum cooling tower 7 (see FIG. 1) is reduced, and the steam that has passed through the steam ejector 6 is guided into the condenser 8.

  FIG. 3 shows a schematic view of the nozzle part constituting the steam ejector 6, and in this embodiment, there are two nozzle parts (first nozzle part 61, second nozzle part 62). explain. In FIG. 3, in order to avoid complication of the drawing, the configuration of the switching means and the like used when switching the two nozzle portions is omitted as a partial sectional view.

  As shown in FIG. 3, when steam is introduced from the first sub-steam supply line 4 to the steam ejector 6, the steam is ejected from a selected nozzle portion in the steam ejector 6. The inside of the vacuum cooling tower 7 is depressurized through the steam suction line 15 connected to the steam ejector 6 by the ejected energy. Further, due to the pressure reducing action caused by the steam ejection energy in the steam ejector 6, the steam in the vacuum cooling tower 7 is sucked, and the sucked steam is mixed in the steam ejector 6 and mixed. The steam is supplied to the condenser 8 side through the steam ejector 6. The steam (mixed steam) discharged from the steam ejector 6 toward the condenser 8 is condensed by exchanging heat with cooling water introduced from the cooling tower 11 (see FIG. 1) to the condenser 8, The condensed water 8a is stored in the condenser 8. FIG. 3 shows a case where steam (first steam S41 and second steam S42) is ejected from both nozzle portions 61 and 62, respectively, but this embodiment is limited to this configuration. Instead, one of the nozzle portions (the first nozzle portion 61 or the second nozzle portion 62) may selectively function as necessary.

Now, as shown in FIG. 3, the steam ejector 6 according to the present embodiment is characterized by having two nozzle portions 61 and 62. Until now, there is only one nozzle portion provided in the steam ejector known as the prior art. However, the inventors of the present invention can use energy more efficiently by providing a plurality of nozzle portions having different performances and selectively using these nozzle portions as shown in the present embodiment. It has been conceived that the steam ejector 6 can be configured. The performance of the steam ejector can be expressed by a mass flow rate ratio (= suction steam amount G ₂ / drive steam amount G ₁ ) (see FIG. 1).

FIG. 4 shows a partially enlarged view of FIG. 3 (an enlarged view of the IV portion). Specifically, the nozzle throat diameter d ₀₁ and the nozzle outlet inner diameter d ₁₁ that define the performance of the first nozzle portion 61 are shown. FIG. Further, “nozzle expansion ratio α” is known as an index for defining the performance of the nozzle portion. “Nozzle expansion ratio α ₁ ” in FIG. 4 is “nozzle expansion ratio α ₁ = (nozzle outlet inner diameter d ₁₁ / Nozzle throat diameter d ₀₁ ) ² ”.

The nozzle portions 61 and 62 constituting the steam ejector 6 according to the present embodiment are configured such that the nozzle expansion ratio α is the same, and the nozzle throat diameter d ₀ and the nozzle outlet inner diameter d ₁ are different. That is, the nozzle expansion ratio of the first nozzle portion 61 alpha ₁ and the nozzle expansion ratio alpha ₂ of second nozzle portion 62 is the same (α _{1 =} α _2), than the nozzle throat diameter d ₀₁ of the first nozzle portion 61 The nozzle throat diameter d ₀₂ of the second nozzle portion 62 is configured to be large (d ₀₂ > d ₀₁ ), and the respective nozzle outlet inner diameters d ₁ (the nozzle outlet inner diameter d ₁₁ of the first nozzle portion 61 and the second nozzle portion 62). The nozzle outlet inner diameter d ₁₂ ) is configured to define the nozzle expansion ratio α to the above condition (α ₁ = α ₂ ).

That is, in the present embodiment, the nozzle expansion ratio α and the nozzle throat diameter d ₀ have the following relationship.
First nozzle portion 61... Nozzle expansion ratio α ₁ ... Nozzle throat diameter d ₀₁
Second nozzle part 62 ... nozzle expansion ratio α ₂ ... nozzle throat diameter d ₀₂
Here, “α ₁ = α ₂ ” and “d ₀₂ > d ₀₁ ”.

  Since the steam ejector 6 according to the present embodiment is configured as described above, the following effects can be obtained.

  As described above, the operating range of the steam ejector is normally set so that the maximum radiation pressure (Pmax) of the steam ejector is set with reference to the summer when the discharge side pressure (condenser side pressure) (Pout) of the steam ejector is the highest. Yes. That is, in summer, the condenser cooling water temperature (corresponding to the “downstream condition of the ejection part” of the present invention) is high, so that the discharge side pressure of the steam ejector 6 becomes high and a large amount of driving steam is required. On the other hand, in winter, the amount of driving steam is not as high as in summer. Therefore, when a steam ejector (steam ejector according to the prior art) configured with one nozzle part is designed as a nozzle part suitable for one season (summer or winter), the performance is improved in the other season. There was a problem of lowering.

On the other hand, in this embodiment, the steam ejector 6 is configured using a nozzle portion group (corresponding to the “spout portion group” of the present invention) composed of a plurality of nozzle portions 61 and 62 having different nozzle throat diameters d _0. Therefore, the problems of the prior art can be easily solved.

The steam ejector 6 according to the present embodiment does not deteriorate in performance even in summer and winter, for example, by properly using the first nozzle portion 61 and the second nozzle portion 62 according to the season. More specifically, in the “summer” in which a large amount of driving steam is required, the second nozzle portion 62 (nozzle throat diameter d ₀₂ ) having a large nozzle throat diameter is used. In “winter” which is not necessary, the first nozzle portion 61 (nozzle throat diameter d ₀₁ ) having a small nozzle throat diameter is used. In this way, if the nozzle part is configured to be switchable, it can be operated with the amount of driving steam according to the season, so that it can be operated in an optimal state throughout the year, increasing operating efficiency and reducing running costs. The steam ejector 6 can be obtained. That is, according to the present embodiment, it is possible to increase the mass flow rate ratio (G2 / G1 (= suction steam amount / drive steam amount)) indicating the efficiency of the steam ejector 6 in summer or winter. It becomes.

  Further, according to the present embodiment, the nozzle portion group (corresponding to the “spout portion” of the present invention) composed of a plurality of nozzle portions (corresponding to the “spout portion” of the present invention) having the same nozzle expansion ratio and different nozzle throat diameters. Therefore, even if the outside air temperature or the like fluctuates, the amount of driving steam can be obtained by normal expansion with the same driving steam pressure.

  In addition, this invention is not limited to the said Example, A various change is possible as needed.

Although the case where two nozzle portions are provided has been described in the above embodiment, the present invention is not limited to this configuration, and three or more nozzle portions may be provided as necessary. For example, when three nozzle portions are provided, the nozzle throat diameter d ₀₃ (d ₀₂ > d ₀₃ > d ₀₁ , the nozzle expansion ratio α located approximately in the middle between the first nozzle portion 61 and the second nozzle portion 62 described above. May be provided, and the nozzle portion may be switched according to the season or the temperature of the day. With such a configuration, for example, the first nozzle unit 61 is used for “winter”, the second nozzle unit 62 is used for “summer”, and the third nozzle unit is used for “spring and autumn”. This makes it possible to operate the steam ejector in a more optimal state throughout the year. As a matter of course, a configuration in which four or more steam nozzle portions are provided and selectively used according to the temperature or the like also belongs to the technical scope of the present invention.

<Second Example>
Next, a second embodiment of the present invention will be described.

  The cold water production system (corresponding to the “decompression system” of the present invention) configured by using the steam ejector according to the second embodiment of the present invention is the same as that of FIG. It is configured using equipment. The difference from the first embodiment is only the steam ejector constituting the cold water production system. The configuration of the steam ejector is basically the same as that of the first embodiment, and only the partial components are different. Therefore, in the following, the steam ejector according to the present embodiment will be mainly described with reference to FIGS. 1 to 4, and the description of the same parts as the first embodiment will be omitted. Note that, since the drawings are the same as those in the first embodiment, the reference numerals are also used as they are, but there are portions having a configuration different from that in the first embodiment.

  Similarly to the first embodiment, the steam ejector 6 according to the present embodiment also has two nozzle portions 61 and 62. However, it has a configuration different from that of the first embodiment.

Specifically, the nozzle portions 61 and 62 constituting the steam ejector 6 according to the present embodiment have a nozzle expansion ratio α (= (nozzle outlet inner diameter d ₁ / nozzle throat diameter d ₀ ) ² ) and nozzle throat diameter d _0. Are configured differently. In this embodiment, the nozzle expansion ratio α ₂ of the second nozzle portion 62 is configured to be larger than the nozzle expansion ratio α ₁ of the first nozzle portion 61 (α ₂ > α ₁ ). In the present embodiment, is configured to than the nozzle throat diameter _{d 01} of the first nozzle portion 61 toward the nozzle throat diameter _{d 02} of the second nozzle portion 62 becomes larger _{(d 02>} d ₀₁₎ . Furthermore, the nozzle outlet inner diameter d ₁ (the nozzle outlet inner diameter d ₁₁ of the first nozzle portion 61 and the nozzle outlet inner diameter d ₁₂ of the second nozzle portion 62) of each of the nozzle portions 61 and 62 is the same as the above-described condition ( α ₂ > α ₁ ).

That is, in the present embodiment, the nozzle expansion ratio α and the nozzle throat diameter d ₀ have the following relationship.
First nozzle portion 61... Nozzle expansion ratio α ₁ ... Nozzle throat diameter d ₀₁
Second nozzle part 62 ... nozzle expansion ratio α ₂ ... nozzle throat diameter d ₀₂
Here, “α ₂ > α ₁ ” and “d ₀₂ > d ₀₁ ”.

  Since the steam ejector 6 according to the present embodiment is configured as described above, the following effects can be obtained.

  As described above, since the steam ejector according to the prior art is usually configured by using one nozzle portion, for example, when there is a temperature change in the vacuum cooling tower 7 constituting the cold water production system (or temperature When changes are required, efficient operation could not be performed. That is, in the cold water production system using the steam ejector according to the prior art, the required cold water (cold water having the required temperature) cannot be efficiently produced.

On the other hand, in this embodiment, steam is generated using a nozzle portion group (corresponding to the “spout portion group” of the present invention) composed of a plurality of nozzle portions 61 and 62 having different nozzle expansion ratios α and nozzle throat diameters d _0. Since the ejector 6 is configured, the above-described problems of the prior art can be easily solved.

  The steam ejector 6 according to the present embodiment, for example, by selectively using the first nozzle portion 61 and the second nozzle portion 62 according to the required cold water temperature, without reducing the operation efficiency of the steam ejector 6, The temperature of the produced cold water can be controlled. More specifically, when the chilled water production temperature is set to a high value, the first nozzle portion 61 having a small nozzle expansion ratio α is selectively used to operate with a reduced amount of driving steam, and the highest radiation pressure is required. Don't be higher than that. Further, when the cold water production temperature is set to be low, the second nozzle portion 62 having a large nozzle expansion ratio α is selectively used to perform operation with high efficiency. That is, according to the present embodiment, the steam ejector 6 can be operated at an optimum mass flow rate ratio (G2 / G1 (= suction steam amount / drive steam amount)) according to the required cold water temperature. It becomes.

  In addition, this invention is not limited to the said Example, A various change is possible as needed.

Although the case where two nozzle portions are provided has been described in the above embodiment, the present invention is not limited to this configuration, and three or more nozzle portions may be provided as necessary. For example, when three nozzle portions are provided, the nozzle expansion ratio α ₃ (α ₂ > α ₃ > α ₁ ) and the nozzle throat diameter that are located approximately in the middle between the first nozzle portion 61 and the second nozzle portion 62 described above. A third nozzle portion having d ₀₃ (d ₀₂ > d ₀₃ > d ₀₁ , the same nozzle expansion ratio α) is provided, and the nozzle portion switching operation is performed in order to adjust the chilled water temperature in three stages (lower>middle> higher). May be performed. As a matter of course, a configuration in which four or more steam nozzle portions are provided, and these are selectively switched according to the cold water temperature to be manufactured is also within the technical scope of the present invention.

<Other examples>
The present invention is not limited to the above-described embodiments and examples, and various modifications can be made as necessary within a range that can be adapted to the spirit of the present invention. Both are included in the technical scope of the present invention.

  In the first embodiment and the second embodiment described above, the present invention has been described with respect to the case where each nozzle portion is selectively used according to the season, the cold water temperature, and the like. It is not limited. Therefore, for example, in each embodiment, a configuration in which two or more nozzle portions are used simultaneously may be employed.

  Moreover, this invention is not limited to the structure of the 1st Example mentioned above and the 2nd Example, It was used in the nozzle part and 2nd Example which were used in the 1st Example as needed. It is good also as a steam ejector which has a nozzle part group (equivalent to "the ejection part group" of the present invention) which combined a nozzle part suitably. According to such a configuration, one or more nozzle portions are selectively used from this nozzle portion group as needed (corresponding to various conditions), so that it is efficient according to more detailed conditions. Can be obtained.

  Furthermore, in the said Example, although the some nozzle part (spout part) was provided in the steam ejector and the structure which used one or more nozzle parts selectively as needed was demonstrated, this invention is It is not limited to this configuration. Therefore, for example, a configuration in which a plurality of steam ejectors (corresponding to the “unit steam ejector” of the present invention) having one or more nozzle portions (spouting portions) are provided and the unit steam ejector is selectively used is also provided by the technology of the present invention. Belong to the scope. That is, in the present invention, a plurality of unit steam ejectors having one or more ejection portions are provided, and one or two unit steam ejectors are provided based on at least one of the upstream condition and the downstream condition of the unit steam ejector. The above unit steam ejector may be configured to be selectively used. Even with such a configuration, it is possible to obtain the same effects as those of the embodiments described above. In the present invention, a plurality of nozzle portions (spouting portions) may be provided in the unit steam ejector, and the nozzle portions may be configured to be appropriately switchable in the unit steam ejector.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic of the cold water manufacturing system comprised using the steam ejector concerning the Example of this invention is shown. It is the schematic which shows an example of the steam ejector which comprises the cold water manufacturing system concerning a present Example. It is a fracture | rupture enlarged view of the nozzle part which comprises the steam ejector in FIG. It is the elements on larger scale of FIG. 3 (enlarged view of the IV section).

Explanation of symbols

1 Engine 2 Exhaust Gas Boiler 3 Main Steam Supply Line 4 First Secondary Steam Supply Line 5 Second Secondary Steam Supply Line 6 Steam Ejector 7 Vacuum Cooling Tower 7A Treated Water Scattering Section 7a Cold Water 8 Condenser 8a Condensed Water 9 Water Sealed Vacuum Pump 10 Discharge pump 11 Cooling tower 11A Fan 11B Sprinkling part 12 Process water supply line 13 Chilled water feed pump 14 Cooling water line 15 Steam suction line 16 Motor valve 61 First nozzle part 62 Second nozzle part S41 Steam (first nozzle part 61 Steam squirting from
S42 steam (steam ejected from the second nozzle part 62)

Claims (6)

A steam ejector having a jetting part for jetting steam,
A jetting part group composed of a plurality of the jetting parts is provided;
A steam ejector characterized in that one or two or more ejection parts in the ejection part group are selectively used based on at least one of an upstream condition and a downstream condition of the ejection part group. The steam ejector according to claim 1, wherein the ejection unit group is configured using different types of ejection units. The steam ejector according to claim 1, wherein the ejection part group is configured using ejection parts having different nozzle throat diameters. The steam ejector according to any one of claims 1 to 3, wherein the ejection unit group is configured using ejection units having different nozzle expansion ratios. A steam ejector having a jetting part for jetting steam,
A plurality of unit steam ejectors having one or more ejection parts are provided,
The steam ejector according to claim 1, wherein one or more of the unit steam ejectors are selectively used based on at least one of an upstream condition and a downstream condition of the unit steam ejector. A decompression system configured using a steam ejector,
A decompression system configured using a steam ejector, wherein the steam ejector is the steam ejector according to any one of claims 1 to 5.

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